On 11/12/2025 10:31 am, Alejandro Vallejo wrote: > Seeing how both you and Andrew seem onboard with dropping cross-vendor support
I found another cross-vendor dropping which you'll want to look into. struct svm_vcpu contains three guest_sysenter_* MSRs. In AMD CPUs, these MSRs only have 32 bits of storage, with the upper halfs write-discard. They are switched via VMLOAD/VMSAVE. However, in the cross-vendor case, the upper halves are needed for 64bit kernels setting up SYSENTER support. Therefore, they're unconditionally intercepted so we can avoid losing the upper half. By dropping cross-vendor support, we can get rid of these fields, allow the guest unconditional access, and simply the MSR intercept logic a little. ~Andrew
